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Major depressive disorder (MDD) is a mental illness with high socio-economic burden, but its pathophysiology has not been fully elucidated. Recently, the cortical excitatory and inhibitory imbalance hypothesis and neuroplasticity hypothesis have been proposed for MDD. Although several studies have examined the neurophysiological profiles in MDD using transcranial magnetic stimulation (TMS), a meta-analysis of TMS neurophysiology has not been performed. The objective of this study was to compare TMS-electromyogram (TMS-EMG) findings between patients with MDD and healthy controls (HCs). To this end, we examined whether patients with MDD have lower short-interval cortical inhibition (SICI) which reflects gamma-aminobutyric acid (GABA)A receptor-mediated activity, lower cortical silent period (CSP) which represents GABAB receptor-mediated activity, higher intracortical facilitation (ICF) which reflects glutamate N-methyl-D-aspartate receptor-mediated activity, and the lower result of paired associative stimulation (PAS) paradigm which shows the level of neuroplasticity in comparison with HC. Further, we explored the effect of clinical and demographic factors that may influence TMS neurophysiological indices. We first searched and identified research articles that conducted single- or paired-pulse TMS-EMG on patients with MDD and HC. Subsequently, we extracted the data from the included studies and meta-analyzed the data with the comprehensive meta-analysis software. Patients with MDD were associated with lower SICI, lower CSP, potentially higher ICF, and lower PAS compared with HC. Our results confirmed the proposed hypotheses, suggesting the usefulness of TMS neurophysiology as potential diagnostic markers of MDD.
Impaired illness awareness or insight into illness (IIA) is a common feature of schizophrenia that contributes to medication nonadherence and poor clinical outcomes. Neuroimaging studies suggest IIA may arise from interhemispheric imbalance in frontoparietal regions, particularly in the posterior parietal area (PPA) and the dorsolateral prefrontal cortex (dlPFC). In this pilot study, we examined the effects of transcranial direct current stimulation (tDCS) on brain regions implicated in IIA.
Eleven patients with schizophrenia with IIA (≥3 PANSS G12) and 10 healthy controls were included. A crossover design was employed where all participants received single-session bi-frontal, bi-parietal, and sham stimulation in random order. For each condition, we measured (i) blood oxygen level-dependent (BOLD) response to an illness awareness task pre- and post-stimulation, (ii) regional cerebral blood-flow (rCBF) prior to and during stimulation, and (iii) changes in illness awareness.
At baseline, patients with schizophrenia showed higher BOLD-response to an illness awareness task in the left-PPA compared to healthy controls. Bi-parietal stimulation reduced the interhemispheric imbalance in the PPA compared to sham stimulation. Relatedly, bi-parietal stimulation increased rCBF beneath the anode (21% increase in the right-PPA), but not beneath the cathode (5.6% increase in the left-PPA). Bi-frontal stimulation did not induce changes in rCBF. We found no changes in illness awareness.
Although single-session tDCS did not improve illness awareness, this pilot study provides mechanistic justification for future investigations to determine if multi-session bi-parietal tDCS can induce sustained changes in brain activity in the PPA in association with improved illness awareness.
Pneumococcal serotype replacement is an important issue after the introduction of pneumococcal conjugate vaccine (PCV) in children. After the introduction of 13-valent PCV, the incidence of invasive pneumococcal diseases (IPD) caused by Streptococcus pneumoniae serotype 12F (Sp12F) have increased in some countries; however, an outbreak of Sp12F has not reported in the post-13-valent PCV era. We experienced a local outbreak of Sp12F during March through May 2016 in Tsuruoka city, Japan after the introduction of 13-valent PCV in 2013. The IPD patients were two children and seven adults, three of whom died with a rapid disease progress. Although the clear transmission route was not determined, eight of the nine patients (89%) had close contact with children, which suggests that transmitted colonisation of Sp12F among children and adults might be the source of transmission. Continuous monitoring of IPDs, along with the determination of pneumococcal serotypes, is warranted in the post–13-valent PCV era. New IPD control strategies may be needed if this fatal outbreak continues to occur.
We report on the detection of long-term X-ray periodicity from the Be/X-ray binary pulsar X Persei. Based on over 23 years of X-ray data observed using RXTE/ASM, Swift/BAT and MAXI/GSC, we confirmed that X Persei exhibits quasi-periodic X-ray flares with a period of ∼7 years. The recurrence timescale corresponds to approximately 10 times its binary orbital period of 250 days. Spectral and hardness ratio changes were not detected along with long-term periodic activity. If we interpret the observed 7 year periodicity of X-ray band flux as a superorbital modulation, then this would be the first observation among the Be/X-ray binaries.
Organic thin-film transistors (OTFTs) are the most promising candidates for flexible electronics owing to their flexible structures, the simplicity of processing large-area devices, and excellent compatibility with flexible substrates. To date, many studies have been reported that have aimed at developing a wide range of plastic electronics such as flexible displays, sensors. In this paper, we discuss our recent work, focusing on OTFT arrays and their application to flexible display. An active-matrix (AM) backplane using a low-temperature cross-linkable olefin-type polymer as the gatedielectric and an air-stable DNTT as the organic semiconductor (OSC) was successfully fabricated on a plastic substrate. The short-channel TFT array exhibited a high hole mobility of over 0.5 cm2/Vs, a low subthreshold slope of 0.31, and excellent environmental and operational stability. A 5-inch flexible OLED display exhibited a high luminescence of over 300 cd/m2 by driving of the DNTT-based OTFTs. Solution-processed OTFTs are also attracting considerable attention owing to both their simple manufacturing process and excellent transistor performance. We present a simple patterning process for a solution-processable OSC that can be used to develop a high-mobility short-channel TFT array. The OSC film was directly patterned on the confined active channel region by a simple lamination coating technique and the resulting TFTs showed a high mobility of up to 1.3 cm2/Vs. In the final section, we report on eco-friendly paper-based organic TFT array. A transparent cellulose nanofibers paper was firstly applied to a flexible substrate for the TFT backplane. A solution-processed TFT on the transparent paper exhibited a high mobility exceeding 1 cm2/Vs, good air stability, and excellent mechanical stability.
Ionization-induced injection into a laser-driven wakefield is studied using 2½D OSIRIS simulations. A laser propagates into a gas mixture of 99.5% helium and 0.5% nitrogen with gas density of each rising linearly from 0 to a peak, after which these remain constant. Simulations show that the process can be controlled by varying the scale length of an up-ramp, the laser intensity, and the maximum plasma density. The injection process is controlled by the bubble radius decreasing as laser propagates up the density gradient and laser self-focusing in the flat-top region. A beam with a central energy of 350 MeV and an energy spread (FWHM) of 1.62% was obtained for an up-ramp length of 135 μm, a normalized vector potential of 2, and a density of 7 × 1018cm−3 (assuming a 0.8 μm wavelength laser).
We have investigated the polycrystalline growth by means of an excimer laser assisted metal organic deposition process and the strategy for the efficient growth. It was revealed that the pulsed photo thermal heating properties must be controlled by changing the laser fluence according to the substrate properties, such as thermal diffusivity. The threshold of the teff value for initial crystal nucleation is approximately 70 ns for oxide thin films. For the fabrication of good quality films with high crystallinity and without a laser ablation of the film surface, it is necessary that the irradiated laser fluence is adjusted to the conditions of teff (efficient annealing time) > 70 ns and Tmax (maximum temperature) < Tm (melting point). Obtained oxide films by using the pulsed UV laser has large crystallite size, and it well functioned to enhance physical properties of films. For further efficient growth for polycrystalline growth of the oxide films, the starting solution containing nanoparticles is very useful: it is named as photo-reaction of nanoparticles process.
The material properties of two ultra low-k organic polymers are characterized for copper interconnect integration. The k-values are 2.2-2.3 for both. Compared to OSG materials of similar k-values, these polymers have lower porosity and smaller pore size, achieved using selfassembled chemistry. Both materials demonstrate excellent resistance to plasma damage: no water uptake was detected after exposure to selected etching plasmas. This characteristic, combined with the small pore size and low porosity, results in the successful integration of the organic low-ks in 80 nm spacing with no significant increase in the integrated k-values.
It is found that higher open porosity in polymer A is accompanied by higher leakage current, which is not however linked to lower dielectric breakdown lifetimes.
The tensile deformation of anisotropic porous copper with unidirectionally oriented cylindrical pores was investigated by an acoustic emission method. In the loadings parallel and perpendicular to the orientation direction of the pores, many cracks are formed after yielding and they strongly affect the deformation. The formed cracks rapidly grow and connect with each other near the peak stress of the stress–strain curve, thereby leading to final fracture. Crack formation is easier under perpendicular loading than under parallel loading, because high stress concentration and stress triaxiality occurs around the pores. As a result, the strength and elongation for perpendicular loading are much smaller than those for parallel loading. Furthermore, in the case of perpendicular loading, the localized deformation around pores drastically decreases the plastic Poisson's ratio. These results indicate that a porous copper macroscopically behaves as a semibrittle material under perpendicular loading, while the porous copper exhibits ductility under parallel loading.
We determined the nucleotide sequences of Norwalk-like viruses in 10 PCR products from stool or oyster specimens obtained from four outbreaks of gastroenteritis in which shellfish was suspected as the cause in Shizuoka prefecture in Japan between 1987–94. The sequences were determined from nucleotide positions 4561–852 (292 bp) in the polymerase region. Two types of sequences were detected. One (genotype 1) had 87% sequence homology with the prototype Norwalk virus, and the other (genotype 2) had 59 % sequence homology. The sequences from isolates belonging to the same genotype were almost the same regardless of the year of isolation. Because sequences of 2 genotypes were detected in 2 of the 4 outbreaks, nested PCR was performed with genotype-specific primers to detect the presence of 2 genotypes in the same specimen. In 5 of 10 specimens, PCR bands were detected with both genotype-specific primers, indicating the coexistence of 2 genotypes in 1 specimen. We also detected two genotypes of Norwalk-like virus in an oyster from a sample implicated in one of the outbreaks which may provide direct evidence of oysters as the cause of the gastroenteritis.
We have demonstrated a 5-inch flexible color liquid crystal display (LCD) and organic light emitting display (OLED) driven by low-voltage operation organic TFT. In order to achieve high-quality and high-resolution moving images, OTFTs with high performances such as a high mobility, high ON/OFF ratio, low sub-threshold slope (SS) and low operating voltage, are developed. We fabricated pentacene-based low-voltage operation OTFT with a Ta2O5 gate dielectric prepared at a low temperature process. The resulting OTFT array showed a high mobility of 0.3-0.4 cm2/Vs, ON/OFF ratio over 107, VTH=2.7V, and low SS=0.3 V/decade. OTFTs with solution-processable materials such as fluoropolymer gate dielectric and liquid-crystalline semiconducting polymers, PBTTT, were also investigated. Electrical characteristics and stabilities of these devices will be discussed. In the final section, we will demonstrate OTFT-driven flexible displays. Both of the flexible LC device and the OLED device were successfully integrated on the pentacene-based OTFT arrays. Printing and lamination techniques were introduced to assemble the flexible LC device. Phosphorescent polymer materials, which can be patterned by ink-jet printing, were used for emitting layer of OLED. Color moving images were successively shown on the resulting 5-inch displays using an active-matrix driving technique of the OTFT at a low driving voltage of 15V.
This paper is overviewed the recent progress on GaN HEMTs. High power, high frequency and high efficiency performance are reported. In addition, the results about long-term reliabilities and good manufacturability demonstrate that GaN HEMTs are ready for mass production.
We studied the effects of anisotropic pores and fiber texture on the fatigue strength and fracture surface of lotus-type porous magnesium fabricated through unidirectional solidification in pressurized hydrogen and argon atmospheres. The fatigue strength in the direction parallel to the longitudinal axis of pores is higher than that in the perpendicular direction. Not only anisotropic pores but also fiber texture grown along the pore direction contributes to the anisotropy in the fatigue strength. The fatigue strength at finite life of lotus magnesium is closely related to the ultimate tensile strength; the fatigue strength is proportional to the ultimate tensile strength for both loadings parallel and perpendicular to the pore direction. The fracture surface of lotus magnesium is not flat, which originates from porous structure. For parallel loading, fiber texture in lotus magnesium also contributes to the irregular surface, i.e., a combination of texture and pore structure affects fracture surfaces.
We studied the effect of anisotropic pore morphology on the fatigue behavior and fracture surface of lotus-type porous copper, which was fabricated through unidirectional solidification in pressurized hydrogen and argon atmospheres. The fatigue strength at finite life is closely related to the pore morphology. The fatigue strength decreases with increasing porosity, and the strength depends on applied-stress direction. The fatigue life is the longest in the direction parallel to the longitudinal axis of cylindrical pores. The fatigue strength at finite life is proportional to the ultimate tensile strength and can be expressed by a simple power-law formula. Anisotropic pores affect the fracture surface of lotus copper; crack-initiation site depends on applied-stress direction, and the anisotropic shape pores affect the direction of crack propagation and final fracture surface.
The near-edge electronic structures of several dyes and phtalocyanines were investigated using Photo-Electron Spectroscopy in Air (PESA). The ionization potentials (IPs) of N3, N719, Z907, D102, D149 and D205 were derived from observed photoemission threshold energies to be 5.88, 5.47, 5.44, 5.53, 5.44 and 5.49eV, respectively. Density of states (DOS) of Fe-, Ni-, Cu- and H2-phthalocyanines were deduced from differentiation of observed photoemission yields with incident photon energies. DOS thus obtained were well compared with calculated ones estimated with use of the DV-Xα molecular orbital calculation method.
Three-dimensional electron motion in a linearly polarized tightly focused laser field is numerically calculated. A high-intensity laser pulse focused on the free electrons in vacuum generates relativistic electron bunches whose length is shorter than the laser wavelength. The extremely short electron bunches with low-energy spread less than 1% are generated for a wide range of the laser parameters.